Abstract
A number of techniques available for removing volatile organic compounds (VOCs) include adsorption, biofiltration and incineration. However, these techniques require further treatment and/or are energy-intensive leading to high treatment costs. Both plasma and photocatalysis are effective and economical alternatives since these two techniques can be operated in ambient conditions resulting in low energy consumption compared to the conventional methods. The main purpose of this work was to apply a combined plasma and photocatalytic system for VOC removal. A four-stage plasma and photocatalytic reactor system was set up to investigate the oxidation of benzene. An increase in either applied voltage or stage number of the plasma reactors enhanced both benzene conversion and CO2 selectivity, which is in contrast with the effects of frequency and feed flow rate. The commercial TiO2 (Degussa P25), sol-gel TiO2, and 1%Pt/sol-gel TiO2 were used as photocatalysts. The presence of all studied photocatalysts hardly affected the benzene conversion but increased markedly the CO2 selectivity. The synergistic effect of photocatalysts presented in the plasma reactor resulted from the activation of TiO2 by the energy generated from the plasma.
